Chemical wastewater is a high concentration of organic matter, salt, hence, is hard to be treated by conventional technology. In order to reduce the amount of refractory material for the follow-up water treatment system, and increase its biological property, the paper tried to improve the catalytic performance of activated carbon by activated carbon steel. By comparison of the influence of different processes for chemical wastewater biological property, we found when the modified activated carbon additive amount is 2 g/L, the ozone dosing quantity is 2 mg/L, the reaction of modified activated carbon catalytic ozone oxidation is treated about 60 min, then the BOD5/CODcr is 0.304. The result can improve the biochemical property more than 90% . It benefits the next step of biochemical treatment. And experiments show that the property of the catalyst is stable, catalytic effect after used multiple times does not change lot. [ABSTRACT FROM AUTHOR]